M-Theory, Cosmology and Quantum Field Theory

Our STFC research programme investigates the fundamental physics that describes matter, interactions and spacetime, focusing on the interrelated core concepts of M-theory, quantum field theory and cosmology.

M-theory, which subsumes string theory and supergravity theory, is our central approach to unifying Einstein's theory of General Relativity with the Standard Model of particle physics. One of the most remarkable features of M-theory is that it incorporates dual descriptions of non-perturbative Yang-Mills theories in terms of strings and branes, leading to profound connections between black holes and quantum field theory and also to new insights into strong coupling phenomena such as quark confinement. These connections will continue play a central role in our research, explored in a number of different ways, including using supersymmetry, novel geometric constructions, new algebraic structures and exactly integrable quantum field theory. An ultimate goal is to determine the fundamental degrees of freedom of M-theory which would have profound implications for understanding quantum gravity as well as ultimately particle physics phenomenology. Black holes are a vital stage for exploring these ideas, and, using both analytical and numerical techniques, we will continue to construct and study black-hole solutions with novel properties that have important implications for understanding the origin of entropy and universal properties of the dual quantum field theories.

Cosmology continues to be a highly vibrant area of study driven by a wealth of new data, in particular via the new field of gravitational waves observations. Key clues to the structure and the origin of the universe are to be found in the details of the cosmic microwave background. These questions provide one focus of our activities both through analysing data and by studying the cosmological implications of the Higgs field and extensions of the Standard Model of particle physics in inflationary scenarios. Central to the analysis of cosmology is the study of effective field theories. A key element of our work is to use fundamental conditions such as quantum consistency and causality to put important constraints of the allowed form of the effective theory, with implications for early-time cosmology, black-hole physics and dark energy. This includes the possibility that Einstein gravity is modified, for instance where the graviton has a mass. More generally our work extends to looking at how to extract general imprints of quantum gravity, such as fundamental discreteness of spacetime, on cosmological data. A unifying theme throughout this research is what information can be extracted from new gravity wave measurements and what this implies about the nature of gravity and how the universe evolved.